Peer review completion

Two reviewers found your paper novel and interesting, but suggested major revisions that are necessary before publication. In particular, Reviewer 2 notes that statistical analyses should be improved by considering that most measurements are related to the same source, where 15N was applied. Thus, calculations have to be conducted accordingly, probably by including distance, biocrust type and their interaction in the analysis, as well as experimental plot as random factor or similar. This should be feasible given your experiment design.

Low amount of water added (only 2mm) has been also presented as an important factor that may affect results obtained in moss dominated biocrust. Following reviewer two suggestions authors must, at least, recognize this issue in the manuscript and also moderate related statements, as well as other speculations within the manuscript that are not proven by the experimental data, some of them already explained in the discussion.

Please address these and the other comments of the reviewers and incorporate all of them into the new version of the manuscript.

I now read a revised version of the manuscript and found that most of my concerns have been treated in an adequate way. The data analysis was conducted in an appropriate way and the results were discussed with greater care.
There is one issue, which is not clear. Whereas in Fig. 1a 14 cyanocrusts were analyzed regarding distance and delta 15N, in Fig. 2a only 11 cyanocrusts were plotted. I wonder what has happened to the remaining samples.

Minor comments:
Line 144: rainfall (“r” is missing)
Line 158: comma after solution
Line 271 ff.: check commas in that sentence
Line 321 ff.: …the number of gene copies of Pleosporales was… or …the numbers of gene copies of Pleosporales were…
Line 325: “large” instead of “larger”
Line 327: Comma before “respectively”
Line 375: disseminated (“d” is missing)

We got the revision of original reviewers and they considered that their concerns have been properly solved. Thus they recommended its publication in biogeosciences, after some minor modifications:

Referee #1

All of my concerns were adequately addressed and it appears they have appropriately addressed the other reviewers' concerns as well. I suggest accepting the manuscript.

Referee #2

I now read a revised version of the manuscript and found that most of my concerns have been treated in an adequate way. The data analysis was conducted in an appropriate way and the results were discussed with greater care.
There is one issue, which is not clear. Whereas in Fig. 1a 14 cyanocrusts were analyzed regarding distance and delta 15N, in Fig. 2a only 11 cyanocrusts were plotted. I wonder what has happened to the remaining samples.

Minor comments:
Line 144: rainfall (“r” is missing)
Line 158: comma after solution
Line 271 ff.: check commas in that sentence
Line 321 ff.: …the number of gene copies of Pleosporales was… or …the numbers of gene copies of Pleosporales were…
Line 325: “large” instead of “larger”
Line 327: Comma before “respectively”
Line 375: disseminated (“d” is missing)